Such a detector is to be gathered, for example, from DE 101 35 288 U1, and is used in an X-ray computer tomograph. An X-ray detector usually includes a number of detector modules that are arranged in a housing in the manner of an array or a matrix. The detector modules are constructed from at least one detector element. Each detector element has on a front end a sensor element that detects the X-rays striking the detector element.
As a rule, the sensor element includes a converter that is excited by the γ quanta of the X-radiation, and a downstream signal transducer for measuring the signals generated by the converter. There is usually arranged upstream of the converter a collimator with the aid of which scattered radiation components are absorbed. The detector element further comprises readout electronics having a number of electronic components. The sensor element and the electronic components are arranged by way of example on a printed circuit board of the detector element.
The signals of the sensor element are evaluated and/or digitized in the electronic components. A not inconsiderable quantity of waste heat that must be dissipated is generated in the components of the detector module during operation. Malfunctioning of the electronic components, and thus of the detector module can come about in the event of intense heating or the accumulation of heat or else in the event of strong temperature fluctuations. Difficulties are caused in this case by the fact that both the electronic components and the transducer elements of the detector such as, for example, the converter and the signal transducer exhibit properties dependent on temperature and must be kept as still as possible in terms of temperature, since specific temperature changes lead to image artifacts.